Internal release agents, active hydrogen containing mixtures which contain such agents and the use thereof in a process for the production of molded products

ABSTRACT

The present invention is directed to a novel internal release agent, a mixture of isocyanate reactive materials containing the release agent and a RIM process using the release agent. The novel release agent is a reaction product of 1) a polyester prepared by reacting (a) a polymerized fatty acid with (b) a relatively low molecular weight hydroxy group containing compound, and 2) a saturated monocarboxylic acid.

BACKGROUND OF THE INVENTION

Internal mold release agents used in the production of moldedpolyurethane and polyurea products are known. U.S. Pat. Nos. 4,201,847and 4,254,228 describe an internal mold release which is the reactionproduct of an organic polyisocyanate and an active hydrogen containingfatty acid ester.

U.S Pat. No. 3,925,527 describes an internal mold release which is thereaction product of a fatty acid ester and an organic monoisocyanate.

U.S. Pat. Nos. 4,519,965 and 4,581,386 describe the use of zinccarboxylates as internal mold release agents for the production ofmolded polyurethane and/or polyurea elastomers.

While these types of internal release agents have met with some success,they are not totally satisfactory for many applications. Twoshortcomings of all internal release agents to date, including thosedescribed above, are i) the inability to release from a bare metal mold,such as steel or aluminum, and ii) the incompatibility of such agentswith other additives typically used in the reaction injection molding("RIM") process.

DESCRIPTION OF THE INVENTION

The present invention is directed to a novel internal mold releaseagent, an active hydrogen containing mixture which contains such agent,and the use thereof in a reaction injection molding ("RIM") process. Thenovel release agents herein comprise the reaction product of

1) a polyester (i) having an OH number of from about 40 to about 160,and preferably from about 85 to about 140, (ii) having an acid number of15 or less, preferably 10 or less, and most preferably less than 3, and(iii) prepared by reacting (a) a polymerized fatty acid with (b) arelatively low molecular weight hydroxy group containing compound,preferably a diol, and

2) a saturated monocarboxylic acid in a COOH to OH equivalent ratio offrom about 10:1 to about 1:10, preferably from about 5:1 to about 1:5,and most preferably about 1:1.

It has been found that the product gives excellent release from avariety of different mold surfaces. Excellent release occurs when themold surface has been pre-sprayed with an external release agent. It hasalso been found that release from a bare metal mold, such as steel oraluminum, is possible without any pre-application of external moldrelease agent to the mold surface. Finally, the release agents hereinare compatible with active hydrogen containing mixtures which aretypically used in the preparation of reaction injection molded ("RIM")parts.

In one preferred embodiment, the reaction products noted above are mixedwith a zinc carboxylate containing from 8 to 24 carbon atms percarboxylate group. When a zinc carboxylate is used, the weight ratio ofthe reaction product of the polyester and monocarboxylic acid to thezinc carboxylate is from about 10:1 to about 3:1.

The polyesters useful herein (i) have OH numbers of from about 40 toabout 160, and preferably from about 85 to about 140, (ii) have acidnumbers of 15 or less, preferably 10 or less, and most preferably lessthan 3, and (iii) are prepared by reacting (a) a polymerized fatty acidwith (b) a relatively low molecular weight hydroxy group containingcompound.

Polymerized fatty acids are known in the art. See, e.g., U.S. Pat. Nos.4,602,079, 4,680,379, 4,853,430 and 4,937,320, the disclosures of whichare herein incorporated by reference. As used herein, and as used in theart, the term "polymerized fatty acids" is intended to mean those chosenfrom the group consisting of the dimers and trimers of unsaturatedaliphatic monoacids containing from 8 to 24 carbon atoms, and mixturesthereof. Specific polymerized fatty acids useful herein are commerciallyavailable from Unichema International under the trademark "Pripol".Specific commercially available polymerized fatty acids include Pripol1008, Pripol 1009 and Pripol 1004.

The polyesters used are prepared by esterifying the polymerized fattyacids with relatively low molecular weight hydroxy group containingcompounds. Such materials are diols, triols and/or polyols. By"relatively low molecular weight" in the context of materials useful toproduce the polyesters is meant a molecular weight of less than about500. Suitable low molecular weight diols and triols include ethyleneglycol, propylene glycol, dipropylene glycol, pentane diols, butanediols, hexanediols, glycerol, trimethylolpropane, pentaerythritol,neopentyl glycol, 2,2,4-trimethyl-1,3-pentane diol, addition products ofalkylene oxides such as ethylene oxide or propylene oxide with thesealcohols, and the like. Neopentyl glycol and 2,2,4-trimethyl-1,3-pentanediol are presently the most preferred hydroxy group containing compoundsused to prepare the polyesters herein.

Preparation of the polyester is most suitably carried out by thecondensation of the diol, triol and/or polyol and acid at temperaturesabove 100° C., preferably at 120° C. to 220° C., optionally in a vacuum,the process of the elimination of water being continued until thedesired hydroxyl and acid numbers have been obtained. The process ofesterification may, of course, be catalyzed with acid or basic catalystsand the water may be eliminated by azeotropic distillation. The productsprepared and used according to the invention contain predominant amountsof hydroxyl groups and may contain small amounts of carboxylic acidgroups.

General techniques for the preparation of the polyesters of the typeuseful herein are generally known and are described in U.S. Pat. Nos.4,201,847, 4,254,228, and 3,925,527, the disclosures of which are hereinincorporated by reference.

The polyesters are then reacted with saturated monocarboxylic acids in aCOOH to OH equivalent ratio of from about 10:1 to about 1:10, preferablyfrom about 5:1 to about 1:5, and most preferably about 1:1. In general,the preferred monocarboxylic acids are those containing one or morealkyl groups of from 4 to 22 carbon atoms. Most preferred are saturatedaliphatic fatty monocarboxylic acids such as stearic acid, isostearicacid, palmitic acid, undecanoic acid, neodecanoic acid, caproic acid,capric acid, myristic acid, pentanoic acid, heptanoic acid, caprylicacid, nonanoic acid, dodecanoic acid, tridecanoic acid, 2-methylbutanoicacid, pivalic acid, 2-ethylhexanoic acid and the like.

The reaction of the monocarboxylic acid with the polyester is generallycarried out at temperatures of from 40°0 to 220° C., preferably from100° to 215° C., under excess pressure, reduced pressure, or, preferablyin the substantial absence of pressure. A catalyst is generally addedafter the water stops distilling over, with dibutyl tin oxide being thepreferred catalyst. While the reaction time is dependent upon the natureand amounts of starting materials, reaction times of from 2 to 8 hoursare generally sufficient. The reaction is considered complete when theacid number is less than 8 and preferably less than 5.

As noted, in one preferred embodiment, the reaction product of thepolyester and the monocarboxylic acid are mixed with a zinc carboxylate.Useful zinc carboxylates are known in the art and are described in U.S.Pat. Nos. 4,519,965 and 4,581,386, the disclosures of which are hereinincorporated by reference. Zinc stearate is the presently preferred zinccarboxylate.

The release agents of the present invention are eminently suitable foruse in the RIM process. As is known, in the RIM process, an isocyanate,and active hydrogen containing compounds are mixed and injected intomolds, where the reactants are allowed to react fully.

Starting polyisocyanate components for use in the RIM process includealiphatic, cycloaliphatic, araliphatic, aromatic and heterocyclicpolyisocyanates of the type described, for example, by W. Siefken inJustus Liebigs Annalen der Chemie, 562, pages 72 to 136. Specificexamples of useful ethylene diisocyanate; 1,4-tetramethylenediisocyanate; 1,6-hexamethylene diisocyanate; 1,12-dodecanediisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and-1,4-diisocyanate and mixtures of these isomers. Additional examplesinclude 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane(German Auslegeschrift 1,202,785 and U.S. Pat. No. 3,401,190), 2,4- and2,6-hexahydrotolylene diisocyanate and mixtures of these isomers.Hexahydro-1,3- and/or -1,4-phenylene diisocyanate; perhydro-2,4'- and/or-4,4'-diphenylmethane diisocyanate; 1,3- and 1,4-phenylene diisocyanate;1,4-and 2,6-tolylene diisocyanate and mixtures of these isomers are alsosuitable in the instant invention. Diphenylmethane-2,4-and/or-4,4'-diisocyanate; naphthylene-1,5-diisocyanate; triphenylmethane-4,4',4"-triisocyanate; polyphenyl polymethylene polyisocyanatesof the type obtained by condensing aniline with formaldehyde, followedby phosgenation and described, for example, in British Patents 874,430and 848,671 may also be used in the present invention; m- andp-isocyanato-phenyl-sulfonyl isocyanates according to U.S. Pat.No.3,454,606; perchlorinated aryl polyisocyanates of the type described,for example, in German Auslegeschrift 1,157,601 (U.S. Pat. No.3,277,138); polyisocyanates containing carbodiimide groups of the typedescribed in German Patent 1,902,007 (U.S. Pat. No. 3,152,162);diisocyanates of the type described in U.S. Pat. No. 3,492,330; andpolyisocyanates containing allophanate groups of the type described, forexample, in British Patent 993,890, in Belgian Patent 761,626 and inpublished Dutch Application 7,102,524 are still further examples ofsuitable isocyanates. Additionally, polyisocyanates containingisocyanurate groups of the type described, for example, in U.S. Pat. No.3,001,973; in German Patents 1,022,789; 1,222,067 and 1,027,394 and inGerman Offenlegungsschriften 1,929,034 and 2,004,408; polyisocyanatescontaining urethane groups of the type described, for example, inBelgian Patent 752,261 or in U.S. Pat. No. 3,394,164; polyisocyanatescontaining acylated urea groups according to German Patent 1,230,778 andpolyisocyanates containing biuret groups of the type described, forexample, in German Patent 1,101,394 (U.S. Pat. Nos. 3,124,605 and3,201,372) and in British Patent 889,050 are also suitable.

Polyisocyanates produced by telomerization reactions of the typedescribed, for example, in U.S. Pat. No. 3,654,106; polyisocyanatescontaining ester groups of the type described for example, in BritishPatents 965,474 and 1,072,956, in U.S. Pat. No. 3,567,763 and in GermanPatent 1,231,688; reaction products of the above-mentioned isocyanateswith acetals according to German Patent 1,072,385 and polyisocyanatescontaining polymeric fatty acid residues, according to U.S. Pat. No.3,455,883 are still further examples of suitable isocyanate.

Aromatic polyisocyanates which are liquid at the processing temperatureare preferably used. The particularly preferred starting polyisocyanatesinclude derivatives of 4,4'-diisocyanato-diphenylmethane which areliquid at room temperature, for example, liquid polyisocyanatescontaining urethane groups of the type obtainable in accordance withGerman Patent 1,618,380 (U.S. Pat. No. 3,644,457). These may be producedfor example, by reacting 1 mol of 4,4'-diisocyanatodiphenylmethane withfrom 0.05 to 0.3 moles of low molecular weight diols or triols,preferably polypropylene glycols having a molecular weight below 700.Also useful are diisocyanates based on diphenylmethane diisocyanatecontaining carbodiimide and/or uretone imine groups of the typeobtainable, for example, in accordance with German Patent 1,092,007(U.S. Pat. No. 3,152,162). Mixtures of these preferred polyisocyanatescan also be used. In general, aliphatic and cycloaliphatic isocyanatesare less suitable for the purposes of the instant invention.

Also preferred are the polyphenyl-polymethylene polyisocyanates obtainedby the phosgenation of an aniline/formaldehyde condensate.

Also necessary for preparing molded products via the RIM process areisocyanate reactive components. These components may be typicallydivided into two groups, high molecular weight compounds having amolecular weight of 400 to about 10,000 and low molecular weightcompounds, i.e. chain extenders, having a molecular weight of 62 to 399.Examples of suitable high molecular weight compounds include thepolyesters, polyethers, polythioethers, polyacetals and polycarbonatescontaining at least 2, preferably 2 to 8 and most preferably 2 to 4isocyanate-reactive groups of the type known for the production ofpolyurethanes.

The high molecular weight polyethers suitable for use in accordance withthe invention are known and may be obtained, for example, bypolymerizing epoxides such as ethylene oxide, propylene oxide, butyleneoxide, tetrahydrofuran, styrene oxide or epichlorohydrin in the presenceof BF₃ or by chemically adding these epoxides, preferably ethylene oxideand propylene oxide, in admixture or successively to componentscontaining reactive hydrogen atoms such as water, alcohols or amines.Examples of alcohols and amines include the low molecular weight chainextenders set forth hereinafter, 4,4'-dihydroxy diphenyl propane,sucrose, aniline, ammonia, ethanolamine and ethylene diamine. It ispreferred to use polyethers which contain substantial amounts of primaryhydroxyl groups in terminal positions (up to 90% by weight, based on allof the terminal hydroxyl groups present in the polyether). Polyethersmodified by vinyl polymers, of the type formed, by example, bypolymerizing styrene or acrylonitrile in the presence of polyether (U.S.Pat. Nos. 3,383,351; 3,304,273; 3,523,093;and 3,110,695; and GermanPatent 1,152,536), are also suitable, as are polybutadienes containingOH groups.

In addition, polyether polyols which contain high molecular weightpolyadducts or polycondensates in finely dispersed form or in solutionmay be used. Such modified polyether polyols are obtained whenpolyaddition reactions (e.g., reactions between polyisocyanates andamino functional compounds) or polycondensation reactions (e.g., betweenformaldehyde and phenols and/or amines) are directly carried out in situin the polyether polyols.

Suitable examples of high molecular weight polyesters include thereaction products of polyhydric, preferably dihydric alcohols(optionally in the presence of trihydric alcohols), with polyvalent,preferably divalent, carboxylic acids. Instead of using the freecarboxylic acids, it is also possible to use the correspondingpolycarboxylic acid anhydrides or corresponding polycarboxylic acidesters of lower alcohols or mixtures thereof for producing thepolyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic,aromatic, and/or heterocyclic and may be unsaturated or substituted, forexample, by halogen atoms. The polycarboxylic acids and polyols used toprepare the polyesters are known and described for example in U.S. Pat.Nos. 4,098,731 and 3,725,952, herein incorporated by reference in theirentirety. Suitable polythioethers, polyacetals, polycarbonates and otherpolyhydroxyl compounds are also disclosed in the above identified U.S.patents. Finally, representatives of the many and varied compounds whichmay be used in accordance with the invention may be found for example inHigh Polymers, Volume XVI, "Polyurethanes, Chemistry and Technology," bySaunders-Frisch, Interscience Publishers, New York, London, Vol. I,1962, pages 32-42 and 44-54, and Volume II, 1964, pages 5-6 and 198-199;and in Kunststoff-Handbuch, Vol VII, Vieweg-Hochtlen, Carl HanserVerlag, Munich, 1966, pages 45-71.

Suitable aminopolyethers which may be used in accordance with thepresent invention as high molecular weight compounds (the molecularweight is always the average molecular weight which may be calculatedfrom the functionality and the content of isocyanate-reactive groups)are those wherein at least about 30 and preferably about 60 to 100equivalent % of the isocyanate-reactive groups are primary and/orsecondary (preferably primary) aromatically or aliphatically (preferablyaromatically) bound amino groups and the remainder are primary and/orsecondary aliphatically bound hydroxyl groups.

In these compounds, the terminal residues carrying the amino groups mayalso be attached to the polyether chain by urethane or ester groups.These "aminopolyethers" are prepared by methods known per se. Forexample, polyhydroxypolyethers such as polypropylene glycol ethers maybe aminated by reaction with ammonia in the presence of Raney nickel andhydrogen (Belgian Patent 634,741). U.S. Pat. No. 3,654,370 describes theproduction of polyoxyalkylene polyamines by reaction of thecorresponding polyol with ammonia and hydrogen in the presence of anickel, copper, chromium catalyst. German Patent 1,193,671 describes theproduction of polyethers containing terminal amino groups byhydrogenation of cyanoethylated polyoxypropylene ethers. Other methodsfor the production of polyoxyalkylene (polyether) amines are describedin U.S. Pat. Nos. 3,155,728 and 3,236,895 and French Patent 1,551,605.The production of polyethers containing terminal secondary amino groupsis described, for example, in French Patent 1,466,708.

Polyhydroxypolyethers of relatively high molecular weight may beconverted into the corresponding anthranilic acid esters by reactionwith isatoic acid anhydride, as described, for example, in GermanOffenlegungschriften 2,019,432 and 2,619,840 and in U.S. Pat. Nos.3,808,250, 3,975,428 and 4,016,143. Polyethers containing terminalaromatic amino groups are formed in this way.

According to German Offenlegungschrift 2,546,536 and U.S. Pat. No.3,865,791, relatively high molecular weight compounds containingterminal amino groups are obtained by reaction of NCO prepolymers basedon polyhydroxypolyethers with enamines, aldimines or ketiminescontaining hydroxyl groups and subsequent hydrolysis.

It is preferred to use amino polyethers obtained by hydrolysis ofcompounds containing terminal isocyanate groups, for example inaccordance with German Offenlegungschrift 2,948,419 or U.S. Pat. No.4,515,923, herein incorporated by reference in its entirety. In thisprocess, polyethers most preferably containing 2 to 4 hydroxyl groupsare reacted with polyisocyanates to form NCO prepolymers and, in asecond step, the isocyanate groups are converted by hydrolysis intoamino groups.

Also useful are amino compounds prepared by reacting the correspondingpolyol with a halogenated nitrobenzene compound such as o- orp-nitrochlorobenzene, followed by the reduction of the nitro group(s) tothe amine as described in U.S. application Ser. No. 183,556, filed onApr. 19, 1988, and in published European Application 0268849, publishedJun. 1, 1988.

The "aminopolyethers" used in accordance with the invention are oftenmixtures of the compounds mentioned by way of example and (on astatistical average) most preferably contain 2 to 4 terminalisocyanate-reactive groups. In the process according to the invention,the "aminopolyethers" may be used in admixture withpolyhydroxypolyethers free from amino groups.

In accordance with the present invention, the high molecular weightcompounds can be used in admixture with up to about 95% by weight basedon the total quantity of active hydrogen containing compounds, of lowmolecular weight chain extenders. Examples of suitable hydroxylgroup-containing chain extenders include ethylene glycol, 1,2- and1,3-propane diol, 1,3- and 1,4- and 2,3-butane diol, 1,6-hexane diol,1,10-decane diol, diethylene glycol, triethylene glycol, tetraethyleneglycol, dipropylene glycol, tripropylene glycol, glycerol andtrimethylol propane.

Preferred chain extenders are amine terminated chain extenders. Suitableamine chain extenders include aromatic polyamines, preferably diamines,having molecular weights of less than 400, especially the stericallyhindered aromatic polyamines, preferably diamines, having molecularweights of less than 400, especially the sterically hindered aromaticdiamines which contain at least one linear or branched alkyl substituentin the ortho-position to the first amino group and at least one,preferably two linear or branched alkyl substituents containing from 1to 4, preferably 1 to 3, carbon atoms in the ortho-position to a secondamino group. These aromatic diamines include 1-methyl-3,5-diethy2,4-diamino benzene, 1-methyl-3,5-diethyl-2,6-diamino benzene,1,3,5-trimethyl-2,4-diamino benzene, 1,3,5-triethyl-2,4-diamino benzene,3,5,3',5'-tetraethyl-4,4'-diamino diphenylmethane,3,5,3',5'-tetraisopropyl-4,4'-diamino diphenylmethane,3,5-diethyl-3',5'-diisopropyl-4,4'-diamino diphenylmethane,3,5-diethyl-5,5'-diisopropyl-4,4'-diamino diphenylmethane,1-methyl-2,6-diamino-3-isopropylbenzene and mixtures of the abovediamines. Most preferred are mixtures of 1-methyl-3,5-diethyl-2,4-diamino benzene and 1-methyl-3,5-diethyl-2,6-diaminobenzene in a weight ratio between about 50:50 to 85:15, preferably about65:35 to 80:20.

In addition, aromatic polyamines may be used in admixture with thesterically hindered chain extenders and include, for example, 2,4- and2,6-diamino toluene, 2,4'- and/or 4,4'-diaminodiphenylmethane, 1,2- and1,4-phenylene diamine, naphthalene-1,5-diamine andtriphenylmethane-4,4',4"-triamine. The difunctional and polyfunctionalaromatic amine compounds may also exclusively or partly containsecondary amino groups such as 4,4'-di-(methylamino)diphenylmethane or1-methyl-2-methylamino-4-amino-benzene. Liquid mixtures of polyphenylpolymethylene-polyamines, of the type obtained by condensing anilinewith formaldehyde, are also suitable. Generally, the nonstericallyhindered aromatic diamines and polyamines are too reactive to providesufficient processing time in a RIM system. Accordingly, these diaminesand polyamines should generally be used in combination with one or moreof the previously mentioned sterically hindered diamines or hydroxylgroup-containing chain extenders.

Other additives which may be used in the RIM process according to thepresent invention include catalysts, especially tin(II) salts ofcarboxylic acids, dialkyl tin salts of carboxylic acids, dialkyl tinmercaptides, dialkyl tin dithioesters and tertiary amines. Preferredamong these catalysts are dibutyl tin dilaurate and1,4-diazabicyclo-(2,2,2)-octane (triethylene diamine), especiallymixtures of these catalysts. The catalysts are generally used in amountsof about 0.01 to 10%, preferably about 0.05 to 2%, based on the weightof the isocyanate reactive component. In some instances, such as wherethe compatibilizer contains tertiary amine groups, no additionalcatalyst may be necessary.

It is also possible to use surface-active additives such as emulsifiersand foam stabilizers. Examples include N-stearyl-N',N'-bis-hydroxyethylurea, oleyl polyoxyethylene amide, stearyl diethanol amide, isostearyldiethanolamide, polyoxyethylene glycol monoleate, apentaerythritol/adipic acid/oleic acid ester, a hydroxy ethyl imidazolederivative of oleic acid, N-stearyl propylene diamine and the sodiumsalts of castor oil sulfonates or of fatty acids. Alkali metal orammonium salts of sulfonic acid such as dodecyl benzene sulfonic acid ordinaphthyl methane sulfonic acid and also fatty acids may also be usedas surface-active additives.

Suitable foam stabilizers include water-soluble polyether siloxanes. Thestructure of these compounds is generally such that a copolymer ofethylene oxide and propylene oxide is attached to a polydimethylsiloxane radical. Such foam stabilizers are described in U.S. Pat. No.2,764,565. In addition to the catalysts and surface-active agents, otheradditives which may be used in the molding compositions of the presentinvention include known blowing agents, cell regulators, flame retardingagents, plasticizers, dyes, fillers and reinforcing agents such as glassin the form of fibers or flakes or carbon fibers. In addition, otherknown internal mold release agents may be blended with the reactionproducts herein. In most cases, and except for the instance where zinccarboxylates are mixed with the reaction products, it is preferred touse the reaction products alone without the addition of any otherinternal mold release agent.

The molded products of the present invention are prepared by reactingthe components in a closed mold. The compositions according to thepresent invention may be molded using conventional processing techniquesat isocyanate indexes ranging from as low as 90 to as high as 400(preferably from 95 to 115) and are especially suited for processing bythe RIM process. In general, two separate streams are intimately mixedand subsequently injected into a suitable mold, although it is possibleto use more than two streams. The first stream contains thepolyisocyanate component, while the second stream contains theisocyanate reactive components and any other additive which is to beincluded. According to the present invention, the internal release agentis added to the isocyanate reactive components. The release agentsherein are generally used in amounts ranging from about 4% to about 12%by weight, based on the weight of all the isocyanate reactivecomponents. This amount of release agent should be used even if mixturesof reaction product of polyester and monocarboxylic acid and zinccarboxylate are used.

The invention is further illustrated but is not intended to be limitedby the following examples in which all parts and percentages are byweight unless otherwise specified.

EXAMPLES

POLYESTER A: A twelve liter flask was charged with 2750 parts of2,2,4-trimethyl-1,3-pentane diol ("TMPD"). Nitrogen was bubbled throughthe flask and the temperature was raised to 160° C. 6025 parts of Pripol1009 dimer acid (available from Unichema International) were slowlyadded with stirring. The temperature was raised to 220° C. after theaddition of the dimer acid was complete. Water was collected in areceiving flask. When the water stopped distilling over, vacuum wasslowly applied to the system, and more water was distilled over (a totalof 375 parts of water was collected). The resultant ester had an acidnumber of 2.6 and a hydroxyl number of 102.

IMR 1: 5000 parts of POLYESTER A were charged to a twelve liter flaskand the temperature was raised to 120° C. 3016 parts of stearic acidwere added slowly to the rapidly stirring polyester. After the additionwas complete, the temperature was raised to about 215° C. Water wascollected in the receiving flask. After the atmospheric cycle, 2 partsof dibutyl tin oxide were added and vacuum slowly applied. 190 parts ofwater were collected. Full vacuum was applied and samples withdrawn foracid number analysis. The final product had an acid number of about 8.

POLYESTER B: A twelve liter flask was charged with 2400 parts ofneopentyl glycol. Nitrogen was bubbled through the flask and thetemperature was raised to 160° C. 6657 parts of Pripol 1009 dimer acidwere slowly added with stirring. The temperature was raised to 220° C.after the addition of the dimer acid was complete. Water was collectedin a receiving flask. When the water stopped distilling over, vacuum wasslowly applied to the system, and more water was distilled over (a totalof 412 parts of water was collected). The resultant ester had an acidnumber of 0.5 and a hydroxyl number of 132.

IMR 2: 4320 parts of POLYESTER B were charged to a twelve liter flaskand the temperature was raised to 120° C. 2884 parts of stearic acidwere added slowly to the rapidly stirring polyester. After the additionwas complete, the temperature was raised to about 215° C. Water wascollected in the receiving flask. After the atmospheric cycle, 2 partsof dibutyl tin oxide were added and vacuum slowly applied. 182 parts ofwater were collected. Full vacuum was applied and samples withdrawn foracid number analysis. The final product had an acid number of about 6.

POLYESTER C: A twelve liter flask was charged with 2400 parts ofneopentyl glycol. Nitrogen was bubbled through the flask and thetemperature was raised to 160° C. 1683 parts of adipic acid were slowlyadded with stirring. The temperature was raised to 220° C. after theaddition of the acid was complete. Water was collected in a receivingflask. When the water stopped distilling over, vacuum was slowly appliedto the system, and more water was distilled over (a total of 412 partsof water was collected). The resultant ester had an acid number of 0.4and a hydroxyl number of 130.

IMR 3: 3671 parts of POLYESTER C were charged to a twelve liter flaskand the temperature was raised to 120° C. 2420 parts of stearic acidwere added slowly to the rapidly stirring polyester. After the additionwas complete, the temperature was raised to about 215° C. Water wascollected in the receiving flask. After the atmospheric cycle, 2 partsof dibutyl tin oxide were added and vacuum slowly applied. 153 parts ofwater were collected. Full vacuum was applied and samples withdrawn foracid number analysis. The final product had an acid number of about 5.

RIM EXAMPLES

In the RIM examples which follow, the following materials:

POLYOL A: a 28 OH number polyether prepared by reacting glycerin with amixture of propylene oxide and ethylene oxide (weight ratio of propyleneoxide to ethylene oxide was about 5:1) and having a primary OH groupcontent of about 88%.

DETDA: an 80/20 mixture of 1-methyl-3,5-diethyl-2,4-and 2,6-phenyldiamine.

POLYOL B: a reaction product of ethylene diamine and propylene oxidehaving an OH number of about 630.

ESTER: a commercially available release agent prepared by reacting 6moles of oleic acid, 1 mole of adipic acid and 2.5 moles ofpentaerythritol; the ester has an acid number of less than 5 and an OHnumber of about 51.

ZNS: zinc stearate.

DMT: dimethyl tin dilaurate.

DBT: dibutyl tin dilaurate.

TED: a 33% solution of triethylene diamine in dipropylene glycol.

L5304: a silicone surfactant available from Union Carbide.

ISO: Mondur PF, available from Mobay corporation; a liquid isocyanate,having an NCO content of about 23%, prepared by reacting tripropyleneglycol with 4,4'-diphenylmethane diisocyanate.

RIM plaques were prepared using a laboratory piston metering unit andclamping unit. The metering unit was a two component instrument having amaximum metering capacity of 0.6 liters. A 300 mm×200 mm×4 mmrectangular mold was used to mold the samples. The mold was firststripped with a mold cleaner (N-methyl pyrrolidinone), then soaped withChemtrend 2006 (available from Chemtrend), and buffed twice. An aluminumtransducer plate (5.5 mm radius) was connected to a force transducermounted in the lid of the mold. The plate was soaked in DMF for an hour,polished with fine steel wool, rinsed with water, and then rinsed withacetone. A RIM shot was then made, and at the appropriate demold time,the lid of the mold was slowly opened. The maximum force required topull the transducer plate from the molded plaque is the release force.The lower the number, the easier the release. The following moldingconditions were used:

Mold Temperature: 65° C.

Component B Temperature: 45° C.

Component A Temperature: 45° C.

Demold time: 45 seconds

RIM EXAMPLES 1 through 5

The formulations used were as set forth in TABLE 1 (Example 1 is acomparative example):

                  TABLE 1                                                         ______________________________________                                        EXAMPLE    1        2      3       4    5                                     ______________________________________                                        B-Side:                                                                       POLYOL A   78.3     72.3   72.3    72.3 72.3                                  DETDA      16.5     16.5   16.5    16.5 16.5                                  POLYOL B   3.0      3.0    3.0     3.0  3.0                                   ZNS        2.0      --     --      --   --                                    DBT        0.1      --     --      0.1  0.1                                   DMT        --       0.1    0.1     --   --                                    TED        0.1      0.1    0.1     0.1  0.1                                   ESTER      --       3.0    --      3.0  --                                    IMR 2      --       --     --      5.0  8.0                                   IMR 1      --       5.0    8.0     --   --                                    A-Side     50.5     50.5   49.9    50.5 50.5                                  ISO                                                                           ______________________________________                                    

In each instance, 15 consecutive shots were made, with the mold releaseforce measured in Newtons for each shot. The average release force afterthe 15 consecutive shots were as follows:

Example 1: 181

Example 2: 186

Example 3: 59

Example 4: 497

Example 5: 85

IMR 3 would not blend with the components of the B-side. The materialwas not tested due to this incompatibility.

When oleic acid was substituted for the stearic acid of IMR 1 and IMR 2,the molded part would not release.

RIM EXAMPLES 6 THROUGH 11

The formulations used were as set forth in Table 2 (Example 11 is acomparative example):

                  TABLE 2                                                         ______________________________________                                        EXAMPLE   6      7        8    9      10   11                                 ______________________________________                                        B-Side:                                                                       POLYOL A  70.8   74.3     73.8 73.8   74.3 78.3                               DETDA     16.5   16.5     16.5 16.5   16.5 16.5                               POLYOL B  3.0    3.0      3.0  3.0    3.0  3.0                                ZNS       --     0.5      1.0  1.0    0.5  2.0                                DBT       --     --       --   --     --   0.1                                DMT       0.1    0.1      0.1  0.1    0.1  --                                 TED       0.1    0.1      0.1  0.1    0.1  0.1                                L5304     1.5    1.5      1.5  1.5    1.5  --                                 IMR 2     4.0    4.0      4.0  --     --   --                                 IMR 1     4.0    --       --   4.0    4.0  --                                 A-Side    49.8   50.1     50.1 50.1   50.1 50.5                               ISO                                                                           ______________________________________                                    

In each instance, 20 consecutive shots were made, with the mold releaseforce measured in Newtons for each shot. The average release force afterthe 20 consecutive shots were as follows:

Example 6: 381

Example 7: 307

Example 8: 354

Example 9: 255

Example 10: 664

Example 11: 440

Although the invention has been described in detail in the foregoing forthe purpose of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art. without departing from the spirit and scope of theinvention except as it may be limited by the claims.

What is claimed is:
 1. A novel release agent comprising the reactionproduct of1) a polyester (i) having an OH number of from about 40 toabout 160, (ii) having an acid number of 15 or less, and (iii) preparedby reacting (a) a polymerized fatty acid selected from the groupconsisting of dimers and trimers of unsaturated aliphatic monoacidscontaining from 8 to 24 carbon atoms, and mixtures thereof, with (b) arelatively low molecular weight hydroxy group containing compoundselected from the group consisting of diols, triols, and/or polyolshaving molecular weights of less than about 500, and 2) a saturatedmonocarboxylic acid selected from those which contain one or more alkylgroups of from 4 to 22 carbon atoms, in a COOH to OH equivalent ratio offrom about 10:1 to about 1:10.
 2. The composition of claim 1 whereinsaid OH number is from about 85 to about 140, said acid number is 10 orless, and said equivalent ratio is from about 5:1 to about 1:5.
 3. Thecomposition of claim 2 wherein said acid number is less than 3 and saidequivalent ratio is about 1:1.
 4. The composition of claim 1 furthercontaining a zinc carboxylate containing from 8 to 24 carbon atoms percarboxylate group, wherein the weight ratio of said reaction product tosaid zinc carboxylate being from about 10:1 to about 3:1.
 5. Thecomposition of claim 1 wherein said low molecular weight compound isselected from the group consisting of neopentyl glycol and2,2,4-trimethyl-1,3-pentane diol.
 6. An active hydrogen group containingmixture comprising:a) one or more compounds having molecular weights offrom 400 to 10,000 and containing at least two isocyanate reactivegroups, b) one or more compounds having molecular weights of 62 to 399containing at least two isocyanate reactive groups, and c) from about 4to about 12% by weight based upon the amount of components a) and b) ofthe reaction product of1) a polyester (i) having an OH number of fromabout 40 to about 160, (ii) having an acid number of 15 or less, and(iii) prepared by reacting (a) a polymerized fatty acid selected fromthe group consisting of dimers and trimers of unsaturated aliphaticmonoacids containing from 8 to 24 carbon atoms, and mixtures thereof,with (b) a relatively low molecular weight hydroxy group containingcompound selected from the group consisting of diols, triols, and/orpolyols having molecular weights of less than about 500, and 2) asaturated monocarboxylic acid selected from those which contain one ormore alkyl groups of from 4 to 22 carbon atoms, in a COOH to OHequivalent ratio of from about 10:1 to about 1:10.
 7. The composition ofclaim 6, wherein said compound having a molecular weight of 62 to 399 isan amine terminated compound.
 8. The composition of claim 6, furthercontaining a zinc carboxylate containing from 8 to 24 carbon atoms percarboxylate group, wherein the weight ratio of said reaction product tosaid zinc carboxylate being from about 10:1 to about 3:5:1.
 9. In aprocess for the preparation of a molded product comprising mixing anisocyanate and an active hydrogen containing material to form a reactionmixture, injecting said reaction mixture into a mold via the RIMprocess, allowing said reaction mixture to fully react to form saidmolded product, and removing said molded product from said mold, theimprovement wherein said reaction mixture contains from about 4 to about12% by weight based upon the amount of active hydrogen containingmaterial of the reaction product of1) a polyester (i) having an OHnumber of from about 40 to about 160, (ii) having an acid number of 15or less, and (iii) prepared by reacting (a) a polymerized fatty acidselected from the group consisting of dimers and trimers of unsaturatedaliphatic monoacids containing from 8 to 24 carbon atoms, and mixturesthereof, with (b) a relatively low molecular weight hydroxy groupcontaining compound selected from the group consisting of diols, triols,and/or polyols having molecular weights of less than about 500, and 2) asaturated monocarboxylic acid selected from those which contain one ormore alkyl groups of from 4 to 22 carbon atoms, in a COOH to OHequivalent ratio of from about 10:1 to about 1:10.